Marine conservationists have condemned the "devastation" of a rare flame shell reef off the west coast of Scotland by a scallop dredger.

The Loch Carron reef near Plockton was "intensively" dredged on two occasions and could take decades to recover.

The dredger was operating legally, but marine conservationist Howard Wood said it represented a "complete failure" of inshore fishery management.

The Scottish government said it would investigate the "worrying" reports.

Flame shells are bivalves that make nests on the sea bed. The reef that forms around the nests is a valuable nursery ground for young scallops, crustaceans and fish.

Many of the flame shell beds that used to be found off the west coast of Scotland have now disappeared and Scottish Natural Heritage considers large beds rare.

Mr Wood, a winner of the international Goldman Environmental Prize for his marine conservation work, said he was "mad and outraged" by the destruction of the bed, which has been photographed and filmed by divers.

Image copyrightChris RickardImage caption
Divers say they have photographed the "plough tracks" on the sea bed caused by the dredger

Image copyrightChris RickardImage caption
The reef beds form an important nursery area for many species

Mr Wood said the damage would also have an economic impact on the local area, as scallop divers who had been sustainably fishing the reef for many years had now lost a valuable source of income.

"They're going to have a hard time over the next few years," he said.

The reef is in Loch Carron, a sea loch to the east of Skye. It is not in a Marine Protected Area (MPA) and can be legally dredged.

But marine biologist Sue Scott, who has lived in the area for 25 years, said the flame shell reefs were a vital habitat for hundreds of species - including the commercially-important scallops.

Ms Scott told the BBC the same dredger had visited the area twice in April, making repeated passes close to the shore.

It is thought to have been the first time in 10-15 years that a dredger has come to the area.

'Just devastating'

She said the reef, which covers about a square kilometre, had been "wrecked".

"Divers have seen hundreds of dead and dying flame shells.

"The seabed has been ripped up and there's damage to marine life - starfish with legs missing, dead squat lobsters, dead spider crabs and smashed sea urchins.

"It's just devastating."

Ms Scott said she could not understand why it was legal for dredgers to cause so much damage.

You can't protect all the flame shell beds, all the time, everywhereBertie Armstrong, Scottish Fishermen's Federation

"They really should be banned from fishing so close inshore. My quibble is with the law not the dredgers," she added.

Bertie Armstrong, from the Scottish Fishermen's Federation, said scallop dredgers were an "economically-important part of the market".

"There are local jobs in local communities from scallop dredging," he said.

"Not all scallops can be hand-dived. It has its place, but the market cannot be supplied just by that.

"Secondly, MPAs exist that protect flame shell beds and we are great supporters of that. But you can't protect all the flame shell beds, all the time, everywhere."

However, the Open Seas organisation, which campaigns to "promote sustainable seafood", said the federation did not represent the interests of 80% of the vessels operating inshore which use creel or dive methods for harvesting shellfish.

Open Seas spokesman Phil Taylor said: "Such reckless damage for the profit of just one boat is subsea scandal. It brings shame on our seafood industry, damages the future of the fishing industry and the productivity of our sea.

"Recent measures designed to manage scallop dredging are totally inadequate. For the sake of our fishing long term, we need fundamental reform of the way we spatially manage bottom-towed fishing."

'Strong measures'

Open Seas has urged the Scottish Environment Minister Roseanna Cunningham to investigate the issue.

A spokeswoman for the Scottish government said: "These reports are worrying and will be investigated.

"But it is worth noting that there are already strong measures in place to protect valuable marine habitats around our coastline.

"We work closely with local communities and the inshore fisheries groups to review what, if any, additional protective measures are required."

"We will continue this dialogue as we seek to balance the need for legitimate and responsible fishing activity whilst simultaneously preserving our incredibly diverse marine environment."